Induced Polarisation (IP) is a survey method which measures the chargeability of materials in the subsurface, such as massive sulphide deposits. These hold a “charge” for a short duration of time, before dissipating, similar to that of a capacitor. A current is directly applied to the ground and the voltage response through time is captured at receiver electrodes.
The most common application for IP surveying is identifying minerals of interest through their IP response, or through locating accessory minerals with a strong IP response, such as locating potential gold sources by detecting accessory sulphides. Other applications include mapping the thickness and extents of landfill deposits or detecting water leaks through dams or embankments.
ERT and IP often go hand in hand as they use similar methods to produce different but complimentary datasets.